Rare earth elements recycling from waste phosphor by dual hydrochloric acid dissolution

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Waste phosphor contains valuable rare earth elements (REEs) like Yttrium (Y), Europium (Eu), Cerium (Ce), and Terbium (Tb).
• Traditional recycling methods for REEs from waste phosphor exhibit low efficiency and high resource consumption.
• Developing advanced recycling techniques is crucial for sustainable REE recovery and resource management.

Purpose of the Study:

• To compare the efficiency of the traditional method with a newly developed Dual Dissolution by Hydrochloric Acid (DHA) method for recycling REEs from waste phosphor.
• To investigate the technical principles and leaching rates of REEs using the DHA method.
• To evaluate the feasibility of the DHA method for industrial applications.

Main Methods:

• Comparative analysis of traditional acid leaching versus the developed Dual Dissolution by Hydrochloric Acid (DHA) method.
• DHA method involves initial acid leaching of red phosphor, followed by alkali sintering of green and blue phosphors, washing, and subsequent acid leaching of insoluble matter.
• Purification of leached REEs using solvent extraction and precipitation techniques.

Main Results:

• The DHA method achieved a significantly higher total leaching rate of 94.6% for REEs, compared to 42.08% for the traditional method.
• Specific leaching rates for Y, Eu, Ce, and Tb were 94.6%, 99.05%, 71.45%, and 76.22%, respectively.
• The DHA method demonstrated reduced consumption of chemicals and energy.

Conclusions:

• The developed Dual Dissolution by Hydrochloric Acid (DHA) method is highly effective for recycling rare earth elements from waste phosphor.
• The DHA method offers superior leaching efficiency and reduced environmental impact compared to traditional approaches.
• The proposed DHA method is a viable and promising technique for industrial-scale REE recycling.